Sudden unexpected death in epilepsy (SUDEP) is when an otherwise healthy person with epilepsy dies without a known cause, such as injury or drowning. Usually, death occurs during or right after a seizure, but it can occur without a seizure. The condition is not well-understood.

This article will discuss SUDEP, its possible causes, and some things that may reduce the risk.

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What Is SUDEP?

SUDEP describes the death of a person with epilepsy when no other cause can be determined. It is the leading cause of death in people with uncontrolled seizures. It affects 1 in 1,000 people with epilepsy each year.

What Causes SUDEP?

An exact cause of SUDEP has not been established. Why it happens is not well-understood, but researchers have identified some possible reasons.


Seizures can cause apnea (temporarily stopping breathing). A pause in breathing that is too long can cause a dangerous lack of oxygen in the blood, preventing enough oxygen from getting to the heart or brain. A convulsive seizure can also cause the person’s airway to become blocked, leading to suffocation.

Brain Function

Seizures may interfere with or suppress functioning in areas of the brain stem that are responsible for breathing, heart rate, and other important functions. This could cause dangerous changes in breathing and heart rate.

Heart Rhythm

While rare, a seizure can cause a dangerous heart rhythm or cardiac arrest.

Other Causes

It’s possible that SUDEP is caused by a combination of factors, such as breathing difficulty, abnormal heart rhythm, and/or changes in brain function.

Researchers are also exploring other possible causes they haven’t identified yet. One area of interest is the noted tendency of people who die of SUDEP to be found lying prone (on their stomachs) in bed.

It’s possible that in this position, during a seizure, the mouth and nose may become partially or fully obstructed and it may be more difficult to expand the chest. If the person is unable to change positions, asphyxia (suffocation) or rebreathing (breathing back in exhaled air) could occur, causing a lack of adequate oxygen to the body.

Because SUDEP often occurs at night, researchers are looking into a possible connection between SUDEP and the circadian (sleep-wake cycle) processes. Breathing during sleep is different from breathing while awake. Apnea, including obstructive sleep apnea, can occur. A person who is asleep may also be less likely to respond to and correct breathing difficulties.

Currently, an explanation for why SUDEP often occurs at night or during sleep has not been fully established, and the research is ongoing.

Risk Factors

Factors that may increase the risk of SUDEP for people with epilepsy include:

  • Uncontrolled and/or frequent seizures: For people with very frequent seizures, the rate of SUDEP is estimated at between 1 in 50 and 1 in 100. The risk increases with the number of seizures (one to two seizures a year increases the risk by 5 times, while three or more seizures a year can increase the risk up to 15 times). It can still occur in people who have few seizures.
  • Generalized convulsive seizures: Previously called tonic-clonic or grand mal seizures. Absence or myoclonic seizures are not believed to increase the risk of SUDEP.
  • Being ages 21 to 40: SUDEP happens more often in this age group compared to other age groups.
  • Seizures that started at a young age
  • Having been living with epilepsy for many years
  • Missing medication doses
  • Alcohol consumption

SUDEP in Children

According to some research, SUDEP is less common in younger children, but other studies have found a similar rate to that of adults. Children who have uncontrolled epilepsy or who experience frequent seizures are at the highest risk.

Other risk factors may include:

  • Early onset of epilepsy
  • The presence of developmental disabilities

Some steps you can take that may reduce the risk of SUDEP include:

  • Talk to your child’s healthcare provider about the risk of SUDEP.
  • Make sure your child is following their treatment plan exactly as prescribed and not missing doses.
  • Check in with their healthcare provider regularly to discuss if adjustments are needed, particularly if they are still having seizures.
  • Avoid seizure triggers as much as possible.
  • Help your child get enough good quality sleep.
  • Make sure all the adults in the child’s life are trained in seizure first aid.
  • Talk to their healthcare provider about if seizure detection devices may be beneficial.

How to Reduce Your Risk

SUDEP can’t always be prevented, but there are some things that can be done which may reduce the risk.

Seizure Control Medical Treatment

The most recommended way to reduce the risk of SUDEP is to control your seizures. It’s important to take your medication as prescribed (don’t miss doses), and to check in with your healthcare provider regularly to see if adjustments are needed.

If seizures can’t be controlled with medication, other treatments may be tried that include:

Avoid Seizure Triggers

If you know what they are, avoid anything that makes you more likely to have a seizure. Even if you can’t avoid them, knowing what triggers your seizures can help you be better prepared.

Some commonly reported seizure triggers include:

  • Time of day/night
  • Sleep deprivation/sleep difficulties
  • Illness
  • Flashing lights or patterns
  • Drinking alcohol (especially heavy alcohol use) or alcohol withdrawal
  • Substance use, such as cocaine or Ecstasy
  • Stress
  • Hormonal changes and menstrual cycle
  • Not eating well or going long times without eating
  • Specific foods
  • Caffeine or other products
  • Dehydration or not enough fluids
  • Low blood sugar
  • Vitamin and mineral deficiencies
  • Certain medications
  • Missed medications

Lifestyle Changes

Some lifestyle choices that may help with seizure control include:

  • Follow your treatment program as prescribed.
  • Try to identify and avoid your triggers (consider tracking your seizures in an epilepsy diary).
  • Get enough good quality sleep.
  • Avoid or limit alcohol.
  • Avoid recreational drugs.
  • Check in regularly with your healthcare providers.
  • Discuss other treatment options with your healthcare provider if your seizures are not controlled by your current treatment.
  • Eat nutritious foods and stay active.
  • Practice stress management.
  • Discuss your risks for seizure emergencies and SUDEP with your epilepsy healthcare provider.

Because SUDEP often occurs at night, there are some sleep-specific steps that may reduce your risk, including:

  • Share a room with another person who can provide help if needed, such as positioning you on your side.
  • Get checked for obstructive sleep apnea and treat it if necessary.
  • Use one of the several available devices that detect seizures and alert family members, medical personnel, or a person you have designated (it has not yet been proven that these devices lower the risk of SUDEP, research is ongoing).

Train Family Members and Coworkers in Seizure First Aid

It’s important to ensure family, friends, and those who regularly spend time with you know seizure first aid and emergency resuscitation measures (including CPR and defibrillator use).

Proper training on what to do is necessary, but some general tips for how to help someone who is having a seizure include:

  • Stay with the person during the seizure.
  • Check if they have a medical alert bracelet or other emergency information.
  • Speak calmly and comfort the person.
  • Keep yourself and others calm.
  • Stay with the person afterward until they are fully awake, alert, able to communicate, and breathing easily (at least 15 to 20 minutes).
  • When the seizure is done, help the person sit in a safe place and calmly explain what happened.
  • Ensure they get home safely by offering to call a taxi, rideshare service, or another person to take them home.

If a person has a generalized convulsive seizure, they may fall, shake or jerk, cry out, and become unaware of their surroundings. This type of seizure requires steps in addition to the general guidelines for seizure. To help someone having this type of seizure, do the following:

  • Ease them down onto the floor.
  • Gently turn them onto one side.
  • Move anything around them that they could hurt themselves on.
  • Place something soft and flat (like a folded jacket) under their head.
  • Remove eyeglasses if they are wearing them.
  • Loosen anything around their neck, such as ties or anything that could make it hard to breathe.
  • Time the seizure and call 911 (or your local emergency number) if it lasts longer than five minutes.

Do not:

  • Hold them down or try to restrict their movements.
  • Put anything in their mouth (they cannot swallow their tongue, and putting something in their mouth could injure them or you).
  • Give mouth-to-mouth/CPR during the seizure (most of the time, they start breathing on their own again after the seizure).
  • Give them food or water until they are fully alert.

Call 911 if:

  • This is the first seizure the person has ever had.
  • They have trouble breathing or waking up after the seizure.
  • The seizure lasts longer than five minutes.
  • They have another seizure soon after the first seizure.
  • The person is injured.
  • The seizure happened in water.
  • They are pregnant.
  • They have a health condition (such as diabetes or heart disease).

Seizure Action Plan

The Epilepsy Foundation offers Seizure Action Plan instructions and a template you can use to help your loved ones be prepared.

Talking to Your Healthcare Provider About SUDEP

Talking to your healthcare provider about SUDEP can help you learn about your risk and discuss measures you can take that may lower your risk.

Some questions you may want to ask your healthcare provider include:

  • Am I at risk for SUDEP?
  • Can I lower my risk (and how)?
  • What should I do if I miss a medication dose or if I am experiencing vomiting/diarrhea?
  • Are my seizures as well-controlled as possible, or should we consider other options?
  • Is there anything I should avoid?
  • What should I tell my friends and family to do if I have a seizure?
  • Is there somewhere local that provides training in seizure first aid?
  • Are there seizure alert devices I should be using?
  • Should I be sharing a room at night?
  • Should I get my heart checked?

This discussion may take some time. Let your healthcare provider know when you book your appointment or at the beginning of the appointment that you have questions about SUDEP, or book a separate appointment so you have plenty of time.

Write down your questions ahead of time, and bring a pen and paper to write down the information given to you by your healthcare provider.

Risk levels for SUDEP can change over time. Follow up with your healthcare provider regularly to discuss how your risks and needs may have changed.


SUDEP is the death of an otherwise healthy person with epilepsy when no other cause can be determined. The exact cause of SUDEP is not known. Frequent and/or uncontrolled general convulsive seizures appear to be the biggest risk factor for SUDEP.

SUDEP can’t always be prevented, but making sure seizures are under control may reduce the risk. It’s also important for friends and family to know how to perform seizure first aid. Talking to your healthcare provider can help you feel well-informed and may bring you some peace of mind.

Frequently Asked Questions

  • How common is SUDEP among those with epilepsy?

    The exact number isn’t known, but it’s estimated that about 1 in 1,000 people with epilepsy may die from SUDEP each year. This number is increased for people with epilepsy whose seizures are not controlled.

  • Can anti-suffocation pillows help to prevent SUDEP?

    These pillows are made for people who are at risk for suffocation, but there isn’t scientific evidence to support using them to prevent SUDEP. If you think they might be beneficial to you or a loved one, talk to your healthcare provider.

  • Is SUDEP genetic?

    Some studies suggest genetic factors are involved in SUDEP, but more research is needed.

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